A conventional fuel cell stack includes fuel cell modules each including a plurality of fuel cells stacked on one another, each fuel cell including a membrane electrode assembly having a power generation portion and two separators interposing the membrane electrode assembly therebetween (for example, see Patent Literature 1).
Each fuel cell disclosed in Patent Literature 1 includes a gas introduction hole and a gas discharge hole, and a coolant introduction hole and a coolant discharge hole. The fuel cell is provided with a gas passage communicating with the gas introduction hole and the gas discharge hole.
A coolant passage communicating with the coolant introduction hole and the coolant discharge hole is provided between the fuel cells adjacent to each other in the fuel cell module.